Tag EMS

Two virulence genes are known to encode a binary photorhabdus insect-related toxin that causes acute hepatopancreatic necrosis disease in shrimp. The pathogenicities of these V. campbellii strains were evaluated through laboratory infection and subsequent histological examination in P. vannamei shrimp. 

The GOAL 2016 global shrimp production survey showed a strong rebound in 2014 (up 10 percent to 4.18 MMT), followed by a decline in 2015 (down 5.4 percent) and another recovery forecast for the next three years. Global production is expected to reach around 4.44 MMT in 2018, barring a new disease crisis. 

At this year’s GOAL conference in Guangzhou, China, leading animal welfare and aquatic animal disease experts will share knowledge about how producers can gird their operations. EMS, EHP, streptococcosis and sea lice will be addressed, as will the latest in area management. 

The nonprofit organization established by the leaders of the Global Aquaculture Alliance is answering the growing need for targeted aquaculture training. Its newly unveiled global online education platform will enable the further development of a sustainable global aquaculture industry. 

Early Mortality Syndrome has devastated farmed shrimp in Asia and Latin America. With better understanding of the pathogen and the development and improvement of novel strategies, shrimp farmers are now able to better manage the disease. 

In analyzing the plasmid sequence from the whole genome sequences of AHPND V. parahaemolyticus (V.p) isolates, researchers identified a clear geographical variation within the plasmid, and developed PCR methods to characterize AHPND V.p isolates as either Mexico-type or Southeast Asia-type. 

The GOAL 2015 Shrimp Production Survey showed that global farmed shrimp production is rebounding from the decrease seen from 2011 to 2013 due to diseases, and is headed to an all-time high of around 4.8 million metric tons in 2017, barring any new crises. 

James Anderson delivered a data-rich survey on global shrimp and finfish production volumes for the Global Aquaculture Alliance at its GOAL conference in October. See the full video of his presentation. 

The digestive systems of shrimp are main entry points for bacterial and viral pathogens, and unfavorable microflora. Natural feed additives that combine different actions have proven effective in improving survival where shrimp are exposed to bacterial pathogens. 

A study confirmed the utility for improved polymerase chain reaction (PCR) detection of the Vibrio bacteria that cause acute hepatopancreatic necrosis disease (AHPND) in asymptomatic shrimp by permitting the shrimp to expire and decompose for several hours prior to preservation and PCR processing. 

Selection for disease resistance has been used in breeding farm animals and can be a viable option to deal with white spot syndrome and acute hepatopancreatic necrosis disease in commercial shrimp culture. In trials, heritability for AHPND resistance was low, while that for WSS was moderate. 

The authors recently performed a study to evaluate immunity to white spot syndrome virus and virulent Vibrio parahaemolyticus in shrimp treated with a new mineral extract additive in pelletized feeds. 

In early 2014, a trial to evaluate the effects of a mixture of Bacillus strains on early mortality syndrome bacteria during the larviculture and nursery phases for shrimp was carried out at a commercial hatchery in Mexico. 

Disease problems on shrimp farms may be partly driven by an interaction between management practices that cause inbreeding in small hatcheries and the amplification by inbreeding of susceptibility to disease and environmental stresses. 

After refilling ponds, surviving microorganisms – including Vibrio parahaemolyticus, which causes EMS in shrimp – may benefit from the availability of nutrients in sediment and water and lack of competing microorganisms.